1.5 ton mini split
 

I am searching for another mini split to add to my el cheapo kozy kool that has served faithfully so far to battle this awful humidity we have in ms. Would be interested in hearing from other members that have the 18,000 btu mini splits the likes and dislikes .

I was going to type out a response but this is still how I fell about my two mini splits.
http://ecorenovator.org/forum/33739-post115.html

The only difference is I would buy the Gree Crown series it has Wifi to control it from your phone.
It still works -20 we don’t get below 0 here very often but when we do I would like this option. I would not need backup heat.

https://www.comfortup.com/heating-an...FdgMgQodx0kAPw

I am sure others will add their experience.

Heats down to 5 degrees.

Thermocore T321S-H218 18000 BTU Ductless Split heat pump 21 SEER built by Gree for Thermospace.

Switch to a Gree Terra if you want heat down to -4 degrees.

If it is in your budget, I would second the recommendation of pinballlooking for a Gree Crown.

If i knew a way to make one that was geothermal that is what i would do . I already have the means to do the loops which is hard for every one else . Just no way to make it geothermal.

Mini splits are heating down to -20 now with 25 seer being as common.

fleabay has a 12000 Btu model with the above specs for about $1000 with the 18,000 Btu model costing a few hundred more

I am thinking of just going 2 ton and being done with it. I almost cool my whole house now with 1 ton during moderate days . Its only a few months a year the mini cant keep up. It stays 75 in here

Grab somebody's old 10 SEER R-22 unit off of craigs list or letgo or faceb00k marketplace and start a project. I got a goodman 2 ton heat pump unit for 50 bucks this month, and saw a few 1.5 ton units for around the same price. It is peak air conditioning season, and just as window units command a premium price this time of year, people are upgrading their existing central units in droves. They are dumping their old air handlers and outdoor units for pennies on the dollar. That stuff that runs on 240 volts is useless to most.

For most, the hardest part of the project is choosing heat exchangers or building them. If you have an easy way to do geothermal, rig the loop to a plate heat exchanger rated 25 to 50 percent larger than the compressor at standard rates (2.5 GPM per ton, 10degF temperature change). If you are resourceful, you can rig a condenser out of a roll of 1/2 inch tubing inside a bucket or barrel. A moonshine worm, if you will. For 2 tons or less, 100 feet of 1/2 inch tubing will easily fit in a 5 gallon bucket. For the homebrew condenser, give it 3 GPM per ton of capacity. Voila, you're done outdoors. Sell the fan and the outdoor heat exchanger to get your money back out of the unit, or leave it in place (disconnected) to disguise what's crammed inside (small water pump and water to refrigerant HX).

Indoors, run whatever you are comfortable with as a cold air source. Indoor heat exchangers can take many forms, shapes, and sizes. Just remember that the thing will be wringing gallons of water out of the air every day during cooling season. I made one out of a cylindrical air cleaner (copper tubing in place of the hepa filter) and a water heater drain pan that does a good job. It had a 3-speed fan in it, so the fan speed is controlled by the control board i put on it (read below). I sourced a TXV from surplus city liquidators for around $20. You can buy prefab fan coils or air boxes for a hefty price.

The control system is easy to rig also. If you find an outdoor unit that works, you can rig the thing to a standard thermostat of your choice with a few wires and a 24VAC control transformer. Indoors, all that needs controlled is the fan, by way of a relay. I have started using the Qunda brand of control boards in my beasts. Same basic controls as a mini split unit. Cool looking indoor display/button panel that is either LED with blinky lights and 7-segment digits or backlit LCD panel. The non-heat pump controls are cheaper than the heat pump controls. The one I rigged to the air cleaner beast was like $50 off amazon. I had to add a few control transformers to work the reversing valve and compressor in the outdoor unit, because the Qunda board switches everything at line voltage.

Or you can buy a mini split (or window shaker) system and save most of the fabrication labor. Just plumb up a water to refrigerant HX instead of the air coil. The thing would look and operate the same indoors, but efficiency would soar due to the ground loop and water pump.

Being our busy season is coming to a end and we will be working less i will have the time to do these projects. Like i said in previous post the vertical loop for geothermal i can get done easily. My only thing would be there would be a ton of pictures asking lots of specific questions for taking apart a mini split . I was under the impression that a mini split couldnt be made into geothermal. If a mini can be well . I will be buying mini splits and converting them all to geothermal . I ll put loops at each one .

The main factor in the conversion is how "smart" the control system is. The older systems with capillary tubes or TX valves are fairly straightforward: disconnecting the air coil and fan is a matter of plumbing/brazing/flaring and a little electrical. The only control factor involved outdoors that is super critical is ensuring the water HX never freezes, ever. This typically only happens in winter with an A/C only unit. With a heat pump, it could happen in heating mode as well. Thus, my recommendation for some extra HX capacity and/or water flow rate.

The newer mini systems (especially variable speed inverter driven) are all over the place as far as system design. Many have electronic expansion valves in them, that are controlled by a PID loop, that gets feedback from some sensor(s). The less complicated controls have 3 thermometers in them. They read indoor ambient/indoor HX temp, outdoor ambient/outdoor HX temp, and compressor discharge temp. So even with these simpler/cheaper rigs, if you change the outdoor HX operating envelope, it could trigger a fault condition. Then the unit would either stop in its tracks or run like crap.

This may work in your favor as far as total project cost. Since the unit will be ground source, low or high ambient temperature operation features can be ignored. With many of the premium rigs, extreme temperature operating efficiency is the reason the unit costs more. Hyper heat, turbo cool, quick chill, etc. modes are the trademark names for these modes where the control shifts gears to achieve different objectives. You can find a less expensive unit without these added functions, and it will perform close to (or better than) the premium unit does in its sweet spot. The less expensive unit won't have half a dozen sensors in it, so the chance of proper modified operation is much higher. Most likely, a good plate HX will be less than the price difference between models of similar capacity.

The more I think on it the more I think I may want to attempt it. That would come to my benifit being I am also doin a project right now for 10kw solar . That would lower my usage. I hope. I always liked mini split being I don't want to do any duct work

I will look for a old mini split and before I buy though. Will put it on here to make sure it won't be a pain to do correct. Being I ant home all the time. They are lazy . They wouldn't go out to reset stuff ever hour or somethin like me .